A rotatable connector device which is mountable on a vehicle such as an automobile or the like includes a stator which is to be fixed mainly on the side of a vehicle body and a rotator which is to be assembled to the side of a steering wheel. The stator and the rotator are assembled together coaxially so as to be rotatable with respect to each other. In addition, a flat cable is accommodated in an accommodation space formed by the stator and the rotator.
The flat cable electrically connects an electric device such as a horn module, an airbag module, an audio control module or the like equipped on the side of the steering wheel and a power supply on the side of the vehicle body to each other.
Such a rotatable connector device which is proposed in, for example, Patent Document 1 includes a retainer provided on a bottom surface of an accommodation space and guides the flat cable to be wound around a rotation axis of the steering wheel.
The retainer described in Patent Document 1 will be described in detail. As shown in FIG. 7, a retainer 40 is provided with a plurality of rotatable rollers 45 and a press guide 46 provided to stand in the vicinity of the rotatable roller 45. It is described that the retainer 40 rotates to assist a flat cable C to be wound and rewound in an accommodation space S and thus the rotatable connector device can follow a steering operation to smoothly rotate.
In more detail, in the accommodation space S, the flat cable S includes an outside wound part Co wound along an inner circumferential surface of an outer casing 32 of a stator 30, a reversed part Cr wound along one of the rotatable rollers 45 rotatably supported by the retainer 40 to turn around in a U shape, and an inside wound part Ci wound along an outer circumferential surface of an inner circumferential cylindrical section 22 of a rotator 20.
It is described that the rotatable connector device having such a structure operates as follows. When the rotator 20 rotates clockwise (in the direction of X in FIG. 7), the reversed part Cr of the flat cable C is pressed onto the press guide 46, and the retainer 40 can rotate clockwise by the pressing force.
By contrast, when the rotator rotates counterclockwise (in the direction Y in FIG. 7), the reversed part Cr of the flat cable C is pulled counterclockwise along the rotatable roller 45, and thus the retainer 40 can rotate counterclockwise.
When the accommodation space S is contaminated with a foreign object such as sand or the like, there is an undesirable possibility that when the rotator 20 rotates, the reversed part Cr of the flat cable C is abraded to cause malfunctioning.
For example, in the case where a contact part of the reversed part Cr of the flat cable C and the press guide 46 is contaminated with a foreign object such as sand or the like when the rotator 20 rotates clockwise, there is an undesirable possibility that the reversed part Cr is rubbed with the foreign object and thus the flat cable C is abraded to cause malfunctioning.